Question for Roger Carp (and others)

[EIS2]

Many of the Lionel display layouts in Rogers book "Lionel Trains, Best Layouts & Store Displays" featured multi-leveled tracks with grades from the lower level to the upper level.  How did Lionel control the acceleration/deceleration on the grades to avoid stalling and derailments?  

I have seen some ways of accomplishing the control of post-war engines on grades, but I never thought any of the methods were particularly good.  I was wondering how Lionel did it.  Of course it would be easy today with cruise control.

I saw several displays when I was a child in the 40's and 50's, but I don't ever remember anyone operating the trains.  As far as I can recall, the trains were just turned on and left unattended, so Lionel must have incorporated something to control the speed of the trains.

Regards...

Earl Staley

[sir james I]

They just used a transformer like a KW or ZW set at different voltages with center pins removed for blocks. They might have added large resisters to smooth the transistion but it would have worked without them.

 

[Roger Carp]

Hi Earl,

 

The question you raise was one Lionel had to help its dealers understand. That's why tips appeared on the instruction materials provided with each display.

 

A good example of what I'm talking about went with the D-264, a two-level display. If you look at the reprinted instruction sheet on page 107 of Lionel Trains: Best Layouts & Store Displays, you can see after the paragraphs explaining how to hook up the wires to the transformer: Operating hint: let the setting of the A-U throttle be determined by the speed of the train on the downgrade portion. Set the B-U dial at a slightly higher voltage so that the train will maintain speed on the upgrade section."

 

I hope this answers your question--Lionel usually provided the necessary information.

 

Thanks,

 

Roger Carp

Senior Editor

[Rescuedtrains]

From the how to assemble Lionel D 190 layout instructions.

"Because of the grades used on this display,  single-motored locomotives should be operated with care so that they do not gain excessive speed on the downgrade and derail on the bottom of the grade. Twin-motored locomotives, however, can be operated at the same voltage all around the track, with little danger of derailment."

[lionelsoni]

From the KW transformer repair manual:

"Note that the circuit breaker does not protect binding post combinations A-B, B-D and C-U."

The same is true of all Lionel postwar multiple-output transformers, although their manuals do not carry the warning.

[ADCX Rob]

Lionel was all over the map on this issue. From the service manaul transformer section:

 

This section:

[JTrains]

lionelsoni

From the KW transformer repair manual:

"Note that the circuit breaker does not protect binding post combinations A-B, B-D and C-U."

The same is true of all Lionel postwar multiple-output transformers, although their manuals do not carry the warning.

Bob: would the "right" way to do this be to isolate the downhill portion's center rail and then feed it from the same post as the rest of the track, but use a rheostat (ala a Lionel #95) to adjust the voltage of the isolated section down to the desired speed?

[lionelsoni]

Yes.  That is the simple straightforward way to solve the problem.  It could have been done with the earliest Lionel technology, and it doesn't need a second transformer output circuit.

There's an even better way that exploits modern semiconductors:  anti-parallel diode pairs in series with the transformer's output, instead of a rheostat.  Two of these pairs can be made from a single bridge-rectifier module; and each module will drop the voltage by about 1 volt.  The advantage is that, unlike a rheostat, the voltage drop changes very little, whether the train draws little current going downhill or much current goint uphill.  This reduces the need to tweak the voltage.  Nevertheless, the module provides a center tap that can be used to adjust in .5-volt steps.

[traindaddy1]

Semi-conductors; anti-parallel diode pairs; bridge-rectifiers; rheostats

Wow!.....So much to learn.

Luv this hobby.

 

[cwburfle]

I thought the question was "How did Lionel instruct customers to control the speed of trains on the grades of display layouts?" not "What is the best way to control the speed of trains on grades?"

[lionelsoni]

Do you feel that there is a problem with further discussion about whether Lionel's method is consistent with their transformer warning and about effective and safe alternatives to it?

In any case, the original question was, "How did Lionel [not customers] control the acceleration/deceleration on the grades [of display layouts] to avoid stalling and derailments?"

[cwburfle]

Do you feel that there is a problem with further discussion about whether Lionel's method is consistent with their transformer warning and about effective and safe alternatives to it?

Please explain how their method is inconsistent with their transformer warnings.
In order to do that, you'll need to explicitly demonstrate where Lionel instructed dealers to use specific posts on specific model transformers., and why its wrong.

The only quote I saw was provided by Roger Carp. It referenced using "A" - "U" and "B" - "U" terminals.

Where is the problem on a postwar ZW or Kw transformers?

 

[lionelsoni]

When the train crosses the gap between blocks powered from the A and B transformer terminals, the pickups effectively connect those A and B terminals together, drawing fault current from a terminal combination that Lionel warned was not protected by the circuit breaker in the KW.  According to their schematic diagrams, all the contemporary Lionel multiple-output transformers that the dealer might have used shared that same design characteristic with the KW.

The problem can be seen by tracing the wiring path on the schematic(s) from the A terminal through the secondary winding to the B terminal and observing that it does not pass through the circuit breaker, which is in series with the U terminal.  The same is true for any pair of the A, B, C, and D terminals of the ZW (or V, VW, or Z).

[cwburfle]

When the train crosses the gap between blocks powered from the A and B transformer terminals, the pickups effectively connect those A and B terminals together, drawing fault current from a terminal combination that Lionel warned was not protected by the circuit breaker in the KW.  According to their schematic diagrams, all the contemporary Lionel multiple-output transformers that the dealer might have used shared that same design characteristic with the KW.

 

That's an issue common to any layout that is wired with multiple blocks. Usually the time that the pickups bridge the gap and connect to both circuits is so short that absolutely nothing happens. Normally a Postwar Lionel #91 circuit breaker won't trip.

I suppose that if someone were to stop the train with pick-ups bridging the gap, and leave it there in neutral for a period of time with both the "A" and "B" circuits energized, with different throttle settings, that something could happen.